Question

How do you factor `r^2 + 2r - 80`?

Answer 1

`r^2+2r-80=(r+10)*(r-8)`

Explanation:

`r^2+2r-80`

=`r^2+2r+1-81`

=`(r+1)^2-9^2`

=`(r+1+9)*(r+1-9)`

=`(r+10)*(r-8)`